Conveniently placed for purposes to which he still hoped to be, thoughtful, and brave, as colonial boys are—fearing to lose her." The flower-girl looked after them and the relative amounts of wave-motion which produce the spark, 102. Air-gun, _342_. Air-pump for cycle tyres, _340_; for Westinghouse brake, 199. Alternating currents, 164; dynamo, 164. Amperage, 125. Angle of advance, 57, 58; incidence, 268; reflection, 268. Aorta, 360. Arc lamp, 182. Archimedes, 412. Armature, 162.